Reflector packages and semiconductor light emitting devices including the same

ABSTRACT

Reflectors for a semiconductor light emitting device include a lower sidewall portion defining a reflective cavity. A substantially horizontal shoulder portion extends outwardly from the sloped lower sidewall portion. The horizontal shoulder portion has a circumferentially extending moat formed therein. An upper sidewall portion extends upwardly from the horizontal shoulder portion.

RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.11/044,779 filed on Jan. 27, 2005 now U.S. Pat. No. 7,326,583 whichclaims the benefit of and priority to U.S. Provisional PatentApplication No. 60/558,314, entitled “Reflector Packages and Methods forForming Packaging of a Semiconductor Light Emitting Device,” filed Mar.31, 2004, the disclosure of which is hereby incorporated herein byreference as if set forth in its entirety.

BACKGROUND OF THE INVENTION

This invention relates to semiconductor light emitting devices andfabricating methods therefore, and more particularly to packaging andpackaging methods for semiconductor light emitting devices.

It is known to provide semiconductor light emitting device type lightsources in packages that may provide protection, color selection,focusing and the like for light emitted by the light emitting device.For example, the light emitting device may be a light emitting diode(“LED”). Various problems may be encountered during packaging of a powerLED for use as a light source. Examples of such possible problems willbe described with reference to the cross-sectional illustrations of apower LED in FIGS. 1 and 2. As shown in FIGS. 1 and 2, a power LEDpackage 100 generally includes a substrate member 102 on which a lightemitting device 103 is mounted. The light emitting device 103 may, forexample, include an LED chip/submount assembly 103 b mounted to thesubstrate member 102 and an LED 103 a positioned on the LEDchip/submount assembly 103 b. The substrate member 102 may includetraces or metal leads for connecting the package 100 to externalcircuitry. The substrate 102 may also act as a heatsink to conduct heataway from the LED 103 during operation.

A reflector, such as the reflector cup 104, may be mounted on thesubstrate 102 and surround the light emitting device 103. The reflectorcup 104 illustrated in FIG. 1 includes an angled or sloped lowersidewall 106 for reflecting light generated by the LED 103 upwardly andaway from the LED package 100. The illustrated reflector cup 104 alsoincludes upwardly-extending walls 105 that may act as a channel forholding a lens 120 in the LED package 100 and a horizontal shoulderportion 108.

As illustrated in FIG. 1, after the light emitting device 103 is mountedon the substrate 102, an encapsulant material 112, such as liquidsilicone gel, is dispensed into an interior reflective cavity 115 of thereflector cup 104. The interior reflective cavity 115 illustrated inFIG. 1 has a bottom surface defined by the substrate 102 to provide aclosed cavity capable of retaining a liquid encapsulant material 112therein. As further shown in FIG. 1, when the encapsulant material 112is dispensed into the cavity 115, it may wick up the interior side ofthe sidewall 105 of the reflector cup 104, forming the illustratedconcave meniscus.

As shown in FIG. 2, a lens 120 may then be placed into the reflectivecavity 115 in contact with the encapsulant material 112. When the lens120 is placed in the cavity 115, the liquid encapsulant material 112 maybe displaced and move through the gap 117 between the lens 120 and thesidewall 105. The encapsulant may, thus, be moved out onto the uppersurface of the lens 120 and/or upper surfaces of the sidewall 105 of thereflector cup 104. This movement, which may be referred to assqueeze-out, is generally undesirable for a number of reasons. In thedepicted package arrangement, the lens will sit on a lower shelf if theencapsulant is not cured in a domed meniscus shape prior to the lensattach step. This may cause the lens to not float during thermal cyclingand fail via delamination of encapsulation to other surfaces or viacohesive failure within the delamination, both of which may affect thelight output. The encapsulant material or gel is generally sticky andmay interfere with automated processing tools used to manufacture theparts. Moreover, the gel may interfere with light output from the lens120, for example, by changing the light distribution pattern and/or byblocking portions of the lens 120. The sticky gel may also attract dust,dirt and/or other contaminants that could block or reduce light outputfrom the LED package 100. The gel may also change the shape of theeffective lens, which may modify the emitted light pattern/beam shape.

After placement of the lens 120, the package 100 is typicallyheat-cured, which causes the encapsulant material 112 to solidify andadhere to the lens 120. The lens 120 may, thus, be held in place by thecured encapsulant material 112. However, encapsulant materials having aslight shrinkage factor with curing, such as a silicone gel, generallytend to contract during the heat curing process. In addition, thecoefficient of thermal expansion (CTE) effect generally causes higherfloating of the lens at elevated temperatures. During cool-down, partshave a tendency to delaminate. As the illustrated volume of encapsulantbeneath the lens 120 shown in FIG. 2 is relatively large, thiscontraction may cause the encapsulant material 112 to delaminate (pullaway) from portions of the package 100, including the light emittingdevice 103, a surface of the substrate 102, the sidewalls 105 of thereflector cup 104 and/or the lens 120 during the curing process. Thedelamination may significantly affect optical performance, particularlywhen the delamination is from the die, where it may cause total internalreflection. This contraction may create gaps or voids 113 between theencapsulant material 112 and the light emitting device 103, lens 120,and/or reflector cup 104. Tri-axial stresses in the encapsulant material112 may also cause cohesive tears 113′ in the encapsulant material 112.These gaps 113 and/or tears 113′ may substantially reduce the amount oflight emitted by the light emitting device package 100. The contractionmay also pull out air pockets from crevices (i.e. reflector) or fromunder devices (i.e., die/submount), which may then interfere withoptical cavity performance.

During operation of the lamp, large amounts of heat may be generated bythe light emitting device 103. Much of the heat may be dissipated by thesubstrate 102 and the reflector cup 104, each of which may act as aheatsink for the package 100. However, the temperature of the package100 may still increase significantly during operation. Encapsulantmaterials 112, such as silicone gels, typically have high coefficientsof thermal expansion. As a result, when the package 100 heats up, theencapsulant material 112 may expand. As the lens 120 is mounted within achannel defined by the sidewalls 105 of the reflector cup 104, the lens120 may travel up and down within the sidewalls 105 as the encapsulantmaterial 112 expands and contracts. Expansion of the encapsulantmaterial 112 may extrude the encapsulant into spaces or out of thecavity such that, when cooled, it may not move back into the cavity.This could cause delamination, voids, higher triaxial stresses and/orthe like, which may result in less robust light emitting devices. Suchlens movement is further described, for example, in United States PatentApplication Pub. No. 2004/0041222. The sidewalls 105 may also helpprotect the lens 120 from mechanical shock and stress.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide methods of packaging asemiconductor light emitting device in a reflector having a moatpositioned between a lower and an upper sidewall thereof, the upper andlower sidewall defining a reflective cavity. Encapsulant material isdispensed into the reflective cavity including the light emitting devicetherein to cover the light emitting device and to form a convex meniscusof encapsulant material in the reflective cavity. The convex meniscusextends from an edge of the moat without contacting the upper sidewallof the reflector. The encapsulant material in the reflective cavity iscured. The light emitting device may be mounted in the reflectivecavity.

In other embodiments of the present invention, curing the encapsulantmaterial is preceded by positioning a lens in the encapsulant material,including collapsing the convex meniscus and moving a portion of theencapsulant material into the moat with the lens. Curing the encapsulantmaterial attaches the lens in the reflective cavity. In alternativeembodiments of the present invention, the encapsulant material is curedto form a lens for the packaged light emitting device from theencapsulant material and the encapsulant material is dispensed to form aconvex meniscus providing a desired shape of the lens. The encapsulantmaterial may include a light converting material, such as a phosphorand/or nano-crystals. The light emitting device may be a light emittingdiode (LED).

In further embodiments of the present invention, a first quantity ofencapsulant material is dispensed and cured and curing the firstquantity of encapsulant material is followed by dispensing a secondquantity of encapsulant material onto the cured first quantity ofencapsulant material to form a second convex meniscus of encapsulantmaterial in the reflective cavity. The second convex meniscus extendsfrom an edge of the moat without contacting the upper sidewall of thereflector. A lens is positioned in the reflective cavity proximate thedispensed second quantity of encapsulant material. In some embodiments,this causes the second dispensed meniscus to break and allow the lens torest on the “first” cured volume meniscus. The height (or float level)of the lens may be controlled by such a method in some embodiments. Thedispensed second quantity of encapsulant material is cured to attach thelens in the reflective cavity. The second convex meniscus and the firstconvex meniscus of encapsulant material may both extend from the sameedge of the moat. In alternative embodiments of the present invention,the moat has an inner edge and an outer edge and the second convexmeniscus of encapsulant material extends from the outer edge of the moatand the first convex meniscus of encapsulant material extends from theinner edge of the moat.

In other embodiments of the present invention, the reflector has aninner moat and an outer moat. The inner moat has an inner edge thereofdefining a first lip and the outer moat has an inner edge thereofdefining a second lip. The first quantity of encapsulant material isdispensed into the reflective cavity to form a convex meniscus ofencapsulant material in the reflective cavity extending from the firstlip. The second quantity of encapsulant material is dispensed into thereflective cavity to form a convex meniscus of encapsulant material inthe reflective cavity extending from the second lip. Positioning thelens may include collapsing the second convex meniscus and moving aportion of the second quantity of encapsulant material into the outermoat with the lens. The second lip may have a height greater than thatof the first lip and the height of the second lip may be selected toprovide a desired position for the lens. The lens may be positioned bymoving the lens into the reflective cavity until it contacts the secondlip.

In further embodiments of the present invention, dispensing a firstquantity of encapsulant material into the reflective cavity includingthe light emitting device includes dispensing a first portion of thefirst quantity of encapsulant material into the reflective cavityincluding the light emitting device. The first portion is sufficient towet the light emitting device without filling the reflective cavity to alevel exceeding a height of the light emitting device. The first portionof the first quantity may be sufficient to substantially cover the lightemitting device without forming air pockets in the encapsulant material.The first portion may be sufficient to fill the reflective cavity to aheight of about 250 microns. A second portion of the first quantity ofencapsulant material is dispensed onto the first portion of the firstquantity of encapsulant material. The second portion may be about twicethe first portion. The second quantity may be about equal to the firstportion of the first quantity. The first portion may be cured beforedispensing the second portion. The first quantity of encapsulantmaterial may include a light converting material, such as a phosphorand/or nano-crystals. The second portion of the first quantity ofencapsulant material may be substantially free of phosphor.

In other embodiments of the present invention, the light emitting devicemay be mounted at about a midpoint of the reflective cavity and theencapsulant material may be dispensed at a point displaced from themidpoint towards a sidewall of the cavity so that the encapsulantmaterial is not dispensed directly onto the light emitting device. Theencapsulant material may be a silicone gel. The first quantity ofencapsulant material may include a phosphor and the second quantity ofencapsulant material may be substantially free of phosphor. The lens maybe advanced into the reflective cavity until it contacts the cured firstquantity of encapsulant material. The first quantity of encapsulantmaterial may be sufficient to establish a desired position for the lensin the reflective cavity. In other embodiments, positioning the lensincludes advancing the lens into the reflective cavity to a positionestablished by the cured first quantity of encapsulant material anddispensing the first quantity of encapsulant material includesdispensing a first quantity of encapsulant material sufficient toestablish a desired position for the lens in the reflective cavity.

In further embodiments of the present invention, reflectors for asemiconductor light emitting device include a sloped lower sidewallportion defining a reflective cavity. A substantially horizontalshoulder portion extends outwardly from the sloped lower sidewallportion. The horizontal shoulder portion has a circumferentiallyextending moat formed therein. An upper sidewall portion extendsupwardly from the horizontal shoulder portion.

In other embodiments of the present invention, an edge of the moat isconfigured to limit wicking of encapsulant material outwardly along thehorizontal shoulder portion to allow formation of a convex meniscus ofencapsulant material dispensed into the reflective cavity. The edge ofthe moat may be a lip. The lip may have a peak having a radius ofcurvature of less than about 50 micrometers (μm).

In further embodiments of the present invention, the horizontal shoulderportion includes both a circumferentially extending inner moatpositioned proximate the lower sidewall portion and a circumferentiallyextending outer moat positioned between the inner moat and the uppersidewall portion. An edge of the inner moat may be configured to limitwicking of encapsulant material outwardly along the horizontal shoulderportion to allow formation of a first convex meniscus of encapsulantmaterial dispensed into the reflective cavity and an edge of the outermoat may be configured to limit wicking of encapsulant materialoutwardly along the horizontal shoulder portion to allow formation of asecond convex meniscus of encapsulant material dispensed into thereflective cavity.

In other embodiments of the present invention the edge of the first moatis a first lip and the edge of the second moat is a second lip. Thefirst lip may have a peak having a radius of curvature of less thanabout 50 micrometers (μm) and the second lip may have a peak having aradius of curvature of less than about 50 μm. The first moat and thesecond moat may be stamped features of the horizontal shoulder portion.The second moat may have a width extending from the second lip to theupper sidewall portion.

In further embodiments of the present invention, the lower sidewallportion is substantially conical and has a minimum diameter of fromabout 1.9 millimeters (mm) to about 3.2 mm and a maximum diameter offrom about 2.6 mm to about 4.5 mm. The lower sidewall portion may have aheight of from about 0.8 mm to about 1.0 mm. The upper sidewall portionmay be substantially oval and have an inner diameter of from about 3.4mm to about 4.2 mm. The upper sidewall portion may have a height of fromabout 0.6 mm to about 0.7 mm. The horizontal shoulder portion may have awidth from the lower sidewall portion to the upper sidewall portion offrom about 0.4 mm to about 0.7 mm. The first moat may have a width fromabout 0.3 mm to about 0.4 mm and the second moat may have a width offrom about 0.3 mm to about 0.4 mm.

In other embodiments of the present invention, the edge of the firstmoat is a first lip having a height relative to bottom end of the lowersidewall portion of from about 0.79 mm to about 0.85 mm and the edge ofthe second moat is a second lip having a height relative to bottom endof the lower sidewall portion of from about 0.79 mm to about 0.85 mm. Inalternative embodiments, the first lip has a height relative to bottomend of the lower sidewall portion of from about 0.79 mm to about 0.85 mmand the second lip has a height relative to bottom end of the lowersidewall portion of from about 0.9 mm to about 1.0 mm.

In further embodiments of the present invention a packaged semiconductorlight emitting device includes a reflector having a sloped lowersidewall portion defining a reflective cavity, a substantiallyhorizontal shoulder portion extending outwardly from the sloped lowersidewall portion, the horizontal shoulder portion having acircumferentially extending moat formed therein and an upper sidewallportion extending upwardly from the horizontal shoulder portion. A lightemitting device is positioned in the reflective cavity. An encapsulantmaterial is provided in the reflective cavity and covering the lightemitting device. The light emitting device may be a light emitting diode(LED) and the encapsulant material may be a silicone gel. Theencapsulant material may include a light converting material, such asphosphor and/or nano-crystals.

In other embodiments of the present invention, the encapsulant materialincludes a first region displaced from the light emitting device that issubstantially free of phosphor and a second region between the firstregion and the light emitting device that includes a phosphor. Thedevice may further include a lens attached to the first region of theencapsulant material and extending therefrom. The lens may extend fromthe encapsulant material over the light emitting device.

In further embodiments of the present invention, an LED lamp packageincludes a substrate and a reflector cup mounted thereon. A portion ofthe upper surface of the substrate is exposed for receiving achip/submount assembly within an opening in the reflector cup. Thereflector cup includes an angled lower sidewall for reflecting lightgenerated by the LED chip and at least one moat surrounding the lowersidewall, with the lower sidewall and the moat separated by at least oneelevated lip. An encapsulant material, such as silicone gel, dispensedwithin the chip cavity may by held by the tip prior to curing or lensmounting. Encapsulant material displaced when a lens is mounted in theLED package may flow into the moat instead of being squeezed onto thesurface of the package or the lens. Some embodiments of the presentinvention include a pair of concentric lips and a pair of concentricmoats for receiving encapsulant material. In other embodiments, thepackage includes an inner lip (closer to the chip cavity) and an outerlip that is higher than the inner lip. In addition to holding anencapsulant material in place prior to curing or lens mounting, theouter lip may further act as a lens stop to allow more accurateplacement of the lens in relation to the LED chip.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are cross-sectional side views illustrating a conventionallight emitting device package;

FIGS. 3A to 3C are cross-sectional side views illustrating methods ofpackaging a light emitting device according to some embodiments of thepresent invention;

FIG. 4A is a top view illustrating a light emitting device packagesuitable for use with some embodiments of the present invention;

FIG. 4B is a cross-sectional side view illustrating the light emittingdevice package of FIG. 4A;

FIG. 5A is a top view illustrating a light emitting device packageaccording to some embodiments of the present invention;

FIG. 5B is a cross-sectional side view illustrating the light emittingdevice package of FIG. 5A;

FIG. 6 is a cross-sectional side view illustrating a light emittingdevice package according to further embodiments of the presentinvention;

FIG. 7 is a cross-sectional side view illustrating a light emittingdevice package according to other embodiments of the present invention;

FIGS. 8A to 8C are cross-sectional side views illustrating methods ofpackaging a light emitting device according to further embodiments ofthe present invention;

FIGS. 9A to 9C are cross-sectional side views illustrating methods ofpackaging a light emitting device according to other embodiments of thepresent invention;

FIGS. 10A to 10C are cross-sectional side views illustrating methods ofpackaging a light emitting device according to yet further embodimentsof the present invention;

FIG. 11 is a flowchart illustrating operations for packaging a lightemitting device according to some embodiments of the present invention;

FIG. 12 is a flowchart illustrating operations for packaging a lightemitting device according to some other embodiments of the presentinvention; and

FIG. 13 is a flowchart illustrating operations for packaging a lightemitting device according to yet further embodiments of the presentinvention.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the size and relative sizes of layers and regions may beexaggerated for clarity. Like numbers refer to like elements throughout.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements may also bepresent. It will be understood that if part of an element, such as asurface, is referred to as “inner,” it is farther from the outside ofthe device than other parts of the element. Furthermore, relative termssuch as “beneath” or “overlies” may be used herein to describe arelationship of one layer or region to another layer or region relativeto a substrate or base layer as illustrated in the figures. It will beunderstood that these terms are intended to encompass differentorientations of the device in addition to the orientation depicted inthe figures. Finally, the term “directly” means that there are nointervening elements. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions, layersand/or sections, these elements, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one element, component, region, layer or section fromanother region, layer or section. Thus, a first element, component,region, layer or section discussed below could be termed a secondelement, component, region, layer or section without departing from theteachings of the present invention.

Various embodiments of the present invention for packaging asemiconductor light emitting device 103 will be described herein. Asused herein, the term semiconductor light emitting device 103 mayinclude a light emitting diode, laser diode and/or other semiconductordevice which includes one or more semiconductor layers, which mayinclude silicon, silicon carbide, gallium nitride and/or othersemiconductor materials, a substrate which may include sapphire,silicon, silicon carbide and/or other microelectronic substrates, andone or more contact layers which may include metal and/or otherconductive layers. In some embodiments, ultraviolet, blue and/or greenlight emitting diodes (“LEDs”) may be provided. Red and/or amber LEDsmay also be provided. The design and fabrication of semiconductor lightemitting devices 103 are well known to those having skill in the art andneed not be described in detail herein.

For example, the semiconductor light emitting device 103 may be galliumnitride-based LEDs or lasers fabricated on a silicon carbide substratesuch as those devices manufactured and sold by Cree, Inc. of Durham,N.C. The present invention may be suitable for use with LEDs and/orlasers as described in U.S. Pat. Nos. 6,201,262; 6,187,606; 6,120,600;5,912,477; 5,739,554; 5,631,190; 5,604,135; 5,523,589; 5,416,342;5,393,993; 5,338,944; 5,210,051; 5,027,168; 5,027,168; 4,966,862 and/or4,918,497, the disclosures of which are incorporated herein by referenceas if set forth fully herein. Other suitable LEDs and/or lasers aredescribed in published U.S. Patent Publication No. US 2003/0006418 A1entitled Group III Nitride Based Light Emitting Diode Structures With aQuantum Well and Superlattice, Group III Nitride Based Quantum WellStructures and Group III Nitride Based Superlattice Structures,published Jan. 9, 2003, as well as published U.S. Patent Publication No.US 2002/0123164 A1 entitled Light Emitting Diodes IncludingModifications for Light Extraction and Manufacturing Methods Therefor.Furthermore, phosphor coated LEDs, such as those described in U.S.application Ser. No. 10/659,241, entitled Phosphor-Coated Light EmittingDiodes Including Tapered Sidewalls and Fabrication Methods Therefor,filed Sep. 9, 2003, the disclosure of which is incorporated by referenceherein as if set forth fully, may also be suitable for use inembodiments of the present invention. The LEDs and/or lasers may beconfigured to operate such that light emission occurs through thesubstrate. In such embodiments, the substrate may be patterned so as toenhance light output of the devices as is described, for example, in theabove-cited U.S. Patent Publication No. US 2002/0123164 A1.

Embodiments of the present invention will now be described withreference to the various embodiments illustrated in FIGS. 3-11. Moreparticularly, some embodiments of a double-cure encapsulation processfor use in packaging a light emitting device 103 are illustrated inFIGS. 3A through 3C. Such a double cure encapsulation process may reduceproblems associated with shrinkage of encapsulant material duringcuring. As will be described herein, for some embodiments of the presentinvention, the double cure process may include three dispense operationsand two cure operations. However, it will be understood that more orless dispense operations and cure operations may also be used inpackaging the light emitting device in other embodiments of the presentinvention. As will also be further described herein, embodiments of thepresent invention also include a multi-dispense operation, leading to afirst cure operation followed by another set of dispense and cureoperations to attach a lens.

As illustrated in FIG. 3A, a first predetermined amount (quantity) of anencapsulant material, including two encapsulant material portions 112,114 in the illustrated embodiments, is dispensed within the cavity 115.The encapsulant material 112, 114 may be, for example, a liquid silicongel, an epoxy or the like. The first portion 112 may be dispensed to wetexposed surface portions of the light emitting device 103, moreparticularly, the led chip/submount assembly 101 of the light emittingdevice 103), and the substrate 102. Portions of the reflector cup 104may also be wet by the initial dispense. In some embodiments of thepresent invention, the quantity of encapsulant material dispensed as thefirst portion 112 is sufficient to wet the light emitting device 103without filling the reflective cavity to a level exceeding the height ofthe light emitting device 103. In some other embodiments of the presentinvention, the quantity of encapsulant material dispensed as the firstportion 112 is sufficient to substantially cover the light emittingdevice 103 without forming any air pockets in the encapsulant material112.

As shown in FIG. 3A, the light emitting device is positioned at about amidpoint 115 m of the reflective cavity 115. The encapsulant materialmay be dispensed from a dispenser 200 at a point 115 d displaced fromthe midpoint 115 m towards a sidewall 105 of the reflective cavity 115so that the encapsulant material 112 is not dispensed directly onto thelight emitting device 103. Dispensing encapsulant material 112 directlyon the light emitting device 103 may cause trapping of bubbles as theencapsulant material 112 passes over the structure of the light emittingdevice 103 from above. However, in other embodiments of the presentinvention, the encapsulant material 112 is dispensed on top of the lightemitting device 103 die in addition to or instead of an offset dispense.Dispensing the encapsulant material 112 may include forming a bead ofthe encapsulant material 112 on an end of a dispenser 200 and contactingthe formed bead with the reflective cavity 115 and/or the light emittingdevice 103 to dispense the bead from the dispenser.

The viscosity and/or other properties of the material used for adispense may be selected such that, for example, wetting occurs withoutbubble formation. In further embodiments of the present invention,coatings may be applied to surfaces contacted by the dispensed materialto speed/retard the wetting rate. For example, using certain knowncleaning procedures that leave microscopic residue, selected surfacesmay be treated and, thus, used to engineer the dynamics of the wettingaction.

Due to the surface properties of the inner surface of the reflector cup104 defining the cavity 115, of the light emitting device 103 and of theencapsulant material 112, dispensed encapsulant material 112, even whendispensed from a point 115 d displaced from the midpoint 115 m of thecavity 115, may flow within the cavity 115 in a manner that could stillcause bubbles in the encapsulant material 112. In particular, theencapsulant material 112 is expected to move or “wick” more rapidlyaround the inner surface of the reflector cup 104 and the sidewalls ofthe light emitting device 103 faster than over the top of the lightemitting device 103. As a result, a bubble could be trapped on a side ofthe cavity 115 opposite from the side where the encapsulant material isdispensed when the side flowing encapsulant material meets and thenencapsulant material flows over the top of the light emitting device103, thus being locally dispensed from above with no side outlet for airflow. Accordingly, the quantity of the first portion of dispensedencapsulant material 112 may be selected to reduce or prevent the riskof forming such bubbles. As such, as used herein, reference to“substantially” covering the light emitting device 103 refers tocovering enough of the structure of the light emitting device 103 sothat such a bubble will not result when the remaining portion 114 of thefirst quantity of encapsulant material 112, 114 is dispensed.

After the initially dispensed encapsulant material 112 is allowed tosettle, the second portion 114 of the first predetermined quantity ofencapsulant material is dispensed into the reflective cavity 115. Thesecond portion 114 of the encapsulant material, in some particularembodiments of the present invention, is about twice the first portion112.

After dispensing all the first quantity of encapsulant material 112,114, the first quantity of the encapsulant material 112, 114 is cured,for example, by a heat treatment, to solidify the encapsulant material112, 114. After curing, the level of the encapsulant material 112, 114within the reflective cavity 115 may drop from the level 114A to thelevel 114B as a result of shrinkage of the encapsulant material 112,114.

In some embodiments of the present invention, the first portion 112 iscured before the second portion 114 is dispensed into the reflectivecavity 115. For example, it is known to add a light converting material,such as a phosphor, nano-crystals, or the like, to the encapsulantmaterial 112, 114 to affect the characteristics of the light emittedfrom the package 100. For purposes of the description herein, referenceswill be made to a phosphor as a light converting material. However, itwill be understood that other light converting materials may be used inplace of phosphor. Depending on the desired color spectrum and/or colortemperature tuning for the package 100, phosphor may be mostbeneficially utilized when positioned adjacent the emitter 103 b, inother words, directly on top of the light emitting device 103. As such,it may be desirable to include a phosphor in the second portion 114while not including a phosphor in the first portion 112. However, as thefirst portion 112 is below the second portion 114, phosphor may settlefrom the second portion 114 into the first portion 112, reducing theeffectiveness of the phosphor addition in the second portion 114.Accordingly, phosphor can be added to the first portion 112 to limitsuch settling and/or the first portion 112 can be cured beforedispensing the second portion 114.

The use of multiple dispenses may also allow the addition of a phosphorpreform/wafer of a desired configuration for light conversion. Inaddition, multiple dispenses may allow for the use of materials havingdifferent indexes of refraction to provide, for example, a buried lens(i.e., formed by the interface between two dispenses of materials withdifferent refractive indexes).

As illustrated in FIG. 3B, a second quantity of encapsulant material 116is dispensed in a predetermined amount onto the cured first quantity ofencapsulant material 112, 114 in the reflective cavity 115. In someparticular embodiments of the present invention the second quantity 116is about equal to the first portion 112 of the first quantity ofencapsulant material 112, 114. The second quantity 116 may besubstantially free of phosphor, however, in other embodiments of thepresent invention, phosphor may also be included in the second quantity116.

As shown in FIG. 3C, before the second quantity of encapsulant material116 is cured, a lens 120 is positioned within the reflective cavity 115and against the second quantity of encapsulant material 116. The secondquantity of encapsulant material 116 is then cured, for example, byheating, to harden the encapsulant material 116 and to attach the lens120 in the reflective cavity 115. In some embodiments of the presentinvention use of a double cure process as described above to encapsulantthe light emitting device 103 in the package 100 may reduce delaminationof the cured encapsulant material 112, 114, 116 from the light emittingdevice 103, the lens 120 and/or the reflector cup 104.

The reflector cup 104 shown in FIGS. 3A-3B is further illustrated inFIGS. 4A-4B. FIG. 4A is a top plan view of the reflector cup 104 showingthe top surfaces of the upper sidewall 105, the lower sidewall 106 and asubstantially horizontal shoulder sidewall portion 108 between the uppersidewall 105 and the lower sidewall 106. FIG. 4B is a cross-sectionalview of the reflector cup 104 taken along line B-B of FIG. 4A.

Alternative reflector cup configurations according to variousembodiments of the present invention will now be described as well asmethods for packaging of a light emitting device using such alternativereflector cup configurations. In various embodiments of the presentinvention, these alternative reflector cup configurations may reduce theincidence and/or amount of squeeze out of encapsulant material oninsertion of a lens into encapsulant material in the reflector cup.FIGS. 5A-5B, 6 and 7 illustrate various alternative reflectorconfigurations as will now be described. FIG. 5A is a top plan view of areflector cup 4 and FIG. 5B is a cross-sectional view of the reflectorcup 4 taken along line B-B of FIG. 5A. FIG. 6 is a cross-sectional viewof a reflector cup 4A and FIG. 7 is a cross-sectional view of areflector cup 4B. Each of the illustrated reflector cups 4, 4A, 4Bincludes an upper sidewall 5, an angled lower sidewall 6 and ahorizontal shoulder portion 8 between the upper sidewall 5 and the lowersidewall 6, together defining a reflective cavity 15. As used hereinwith reference to the shoulder portion 8, “horizontal” refers to thegeneral direction in which the shoulder portion 8 extends between thelower sidewall portion 6 and the upper sidewall portion 8 (i.e., ascompared to the lower 6 and upper 5 sidewall portions), not to theparticular angle of the shoulder portion 8 at any intermediate portionthereof (see, e.g., FIG. 7 where the horizontal shoulder portion mayactually have some change in vertical height between the lower 6 andupper 5 sidewall portions to accommodate other features thereof). Inaddition, each of the reflector cups 4, 4A, 4B may include at least onemoat 18 surrounding the lower sidewall 6, with the moat 18 beingseparated from the lower sidewall 6 by a lip (i.e., a projecting edge)22. The moat 18 is illustrated as formed in the shoulder portion 8.

In the embodiments of FIGS. 5A-5B, the moat 18 could be formed bystamping, in which case the lip 22 between the moat 18 and the lowersidewall 6 may be provided with a sharp edge instead of a flat surface.However, it will be understand that, due to the limitations of thefabricating processes used, the flat surface of the lip 22 schematicallyillustrated in FIG. 5B may actually have a more rounded profile. Toomuch of a rounded profile may be undesirable as will be furtherdescribed with reference to FIGS. 8A-8C.

Further embodiments of a reflector cup 4A will now be described withreference to the cross-sectional view of FIG. 6. As shown in FIG. 6, afirst moat 18 is formed between the upper sidewall 5 and the lowersidewall 6, with a first or inner lip 22 separating the lower sidewall 6and the first moat 18. A second moat 24 is formed between the uppersidewall 5 and the first moat 18. A second or outer lip 26 separates thesecond moat 24 from the first moat 18.

Yet further embodiments of a reflector cup 4B will now be described withreference to the cross-sectional view of FIG. 7. As shown in FIG. 7, afirst moat 18 is formed between the upper sidewall 5 and the lowersidewall 6, with a first or inner lip 22 separating the lower sidewall 6and the first moat 18. A second moat 24 is formed between the uppersidewall 5 and the first moat 18. A second or outer lip 26′ separatesthe second moat 24 from the first moat 18. As illustrated in FIG. 7, thesecond lip 26′ is elevated with respect to the first lip 22.

In particular embodiments of the present invention, the first lip 22 hasa peak having a radius of curvature of less than about 50 micrometers(μm) and the second lip 26, 26′ has a peak having a radius of curvatureof less than about 50 μm. The first moat 18 and the second moat 24 maybe stamped features of the horizontal shoulder portion 8. As shown inFIGS. 6 and 7, the second moat 24 may have a width extending from thesecond lip 26, 26′ to the upper sidewall portion 5.

In some embodiments of the present invention, the sloped lower sidewallportion 6 may be substantially conical and may have a minimum diameterof from about 1.9 millimeters (mm) for a 500 μm light emitting devicechip to about 3.2 mm for a 900 μm light emitting device chip and amaximum diameter of from about 2.6 mm for a 500 μm light emitting devicechip to about 4.5 mm for a 900 μm light emitting device chip and aheight of from about 0.8 mm to about 1.0 mm. The upper sidewall portionmay be substantially oval and have an inner diameter of from about 3.4mm to about 5.2 mm and a height of from about 0.6 mm to about 0.7 mm.The horizontal shoulder portion may have a width from the lower sidewallportion to the upper sidewall portion of from about 0.4 mm to about 0.7mm. It will be understood that, as used herein, the terms “oval” and“conical” are intended to encompass circular, cylindrical and othershapes, including irregular shapes based on the fabrication technologyused to form the reflector cup 4, 4A, 4B that may, nonetheless, incombination with a substrate 2 or otherwise, operate to provide areflector for the light emitting device 103 and retain and harden anencapsulant material 12, 14, 16 therein.

In some embodiments of the present invention, the first moat 18 has awidth from about 0.3 mm to about 0.4 mm and the second moat 24 has awidth of from about 0.3 mm to about 0.4 mm. As illustrated in FIG. 6,the edge of the first moat 18 may be a first lip 22 having a heightrelative to a bottom end (i.e. a top surface of the substrate 2) of thelower sidewall portion 6 of from about 0.79 mm to about 0.85 and theedge of the second moat 24 may be a second lip 26 having a heightrelative to bottom end of the lower sidewall portion 6 of from about0.79 mm to about 0.85 mm. In other embodiments of the present inventionas illustrated in FIG. 7, the first lip 22 has a height relative to abottom end of the lower sidewall portion of from about 0.79 mm to about0.85 mm and the second lip 26′ has a height relative to a bottom end ofthe lower sidewall portion of from about 0.9 mm to about 1.0 mm.

The reflector cups 4, 4A, 4B, in various embodiments of the presentinvention may, provide for meniscus control when packaging the lightemitting device 103 in a reflector cup 4, 4A, 4B. As will be furtherdescribed, when combined with the double cure methods described above, adistinct convex meniscus may also be provided for different dispenses ofencapsulant material and, as a result, the incidence of doming failuremay be reduced. In other embodiments of the present invention, theprovided meniscus control may reduce the difficulty of lens placement ata desired depth and/or angle, reduce lens wicking or squeeze-out ofencapsulant material onto the top of the lens and/or allow forconfiguration of the optical characteristics of the packaged lightemitting device. For example, phosphor may be concentrated in the center(midpoint) of the package by doming (convex meniscus) of phosphor loadedencapsulant material over the midpoint of the package.

Different optical patterns (viewing angles, custom color spectrums,color temperature tuning and the like) may be provided by using multiplemeniscus control techniques in combination with dispensing and/or curingvariations in the process. For example, a high peaked dome of a phosphorloaded material may provide greater color spectrum uniformity of whitetemperature light emission with less shift to yellow towards the edgesof the reflector cup by providing a more uniform length of the lightpath through the phosphor loaded material from the light emittingdevice. Similarly, where desired, a greater color spectrum variationfrom white at the midpoint to yellow at the edges may be provided by aflatter dome. In some other embodiments of the present invention, whereprotection related functionality is provided by features other than alens, meniscus control may allow for packaging a light emitting devicewithout a lens by using the encapsulant material as the lens, with themeniscus being configured to provide the desired lens shape.

FIGS. 8A-8C illustrate methods of packaging a light emitting device,using the structural characteristics of a reflector cup for meniscuscontrol, according to some embodiments of the present invention. Theoperations illustrated in FIGS. 8A-8C utilize the reflector cup 4illustrated in FIGS. 5A-5B and the double culling operations alsopreviously described. As shown in FIG. 8A, a first quantity 14 ofencapsulant material is deposited in the reflective cavity 15 of thepackage 10A. In some embodiments of the present invention, the firstquantity 14 may be dispensed using a separate (wetting) dispense andsecond dispense. With proper control of the amount of encapsulantmaterial dispensed, surface tension will cause the liquid encapsulantmaterial 14 to cling to the lip 22, forming a convex meniscus asillustrated in FIG. 8A at a height indicated at 14A. Thus, the lip 22may be used to prevent the dispensed encapsulant material 14 fromcontacting and wicking up the upper sidewall 5 and forming a concavemeniscus as shown in FIG. 1.

The dispensed encapsulant material 14 is cured, for example, by heating,and may shrink down to a height indicated at 14B. As shown in FIG. 8B, asecond quantity 16 of encapsulant material is then dispensed into thecavity 15 on the cured first quantity 14 of encapsulant material. Insome embodiments, as illustrated in FIG. 8B, the second quantity 16 ofencapsulant material may also cling to the same edge of the lip 22 toform a convex meniscus. In other embodiments, the lip 22 may have aninner and outer edge thereon and the second quantity 16 of encapsulantmaterial may cling to the outer edge and the first quantity 14 may clingto the inner edge. Thus, the second quantity 16 of encapsulant materialmay also not contact or wick up the upper sidewall 5 to form a concavemeniscus.

Referring to FIG. 8C, the lens 20 is inserted into reflective cavity 15and brought into contact with the uncured liquid encapsulant material16. As such, the encapsulant material 16 may be squeezed out fromunderneath the lens 20. However, in some embodiments of the presentinvention, instead of squeezing out onto the exposed upper surfaces ofthe reflector cup and the lens (as shown in FIG. 2), the excess of theencapsulant material 16 is squeezed into and received by the moat 18,thus limiting wicking of the encapsulant material 16 up the sidewall 5even after the lens 20 is inserted and the convex meniscus shown in FIG.8B is displaced. The encapsulant material 16 is then cured to attach thelens 20 in the package 10A and to solidify the encapsulant material 16.

FIGS. 9A-9C illustrate methods of packaging a light emitting device,using the structural characteristics of a reflector cup for meniscuscontrol, according to some embodiments of the present invention. Theoperations illustrated in FIGS. 9A-9C utilize the reflector cup 4Aillustrated in FIG. 6 and the double curing operations also previouslydescribed. As shown in FIG. 9A, a first quantity 14 of encapsulantmaterial is deposited in the reflective cavity 15 of the package 10B. Insome embodiments of the present invention, the first quantity 14 may bedispensed using a distinct first (wetting) dispense and a seconddispense after wetting of the light emitting device. With proper controlof the amount of encapsulant material dispensed, surface tension willcause the liquid encapsulant material 14 to cling to the inner lip 22,forming a convex meniscus as illustrated in FIG. 9A at a heightindicated at 14A. Thus, the inner lip 22 may be used to prevent thedispensed encapsulant material 14 from contacting and wicking up theupper sidewall 5 and forming a concave meniscus as shown in FIG. 1.

The dispensed encapsulant material 14 is cured, for example, by heating,and may shrink down to a height indicated at 14B. As shown in FIG. 9B, asecond quantity 16 of encapsulant material is then dispensed into thereflective cavity 15 on the cured first quantity 14 of encapsulantmaterial. In some embodiments, as illustrated in FIG. 9B, the secondquantity 16 of encapsulant material clings to the outer lip 26, forminga convex meniscus. Thus, the outer lip 26 may be used to prevent thedispensed second quantity 16 of encapsulant material from contacting andwicking up the upper sidewall 5 and forming a concave meniscus as shownin FIG. 1.

Referring to FIG. 9C, the lens 20 is inserted into reflective cavity 15and brought into contact with the uncured liquid encapsulant material16. As such, the encapsulant material 16 may be squeezed out fromunderneath the lens 20. However, in some embodiments of the presentinvention, instead of squeezing out onto the exposed upper surfaces orthe reflector cup and the lens (as shown in FIG. 2), the excess of theencapsulant material 16 is squeezed into and received by the second moat24, thus limiting wicking of the encapsulant material 16 up the sidewall5 even after the lens 20 is inserted and the convex meniscus shown inFIG. 9B is displaced. The encapsulant material 16 is then cured toattach the lens 20 in the package 10B and to solidify the encapsulantmaterial 16.

FIG. 9C further illustrates that, in some embodiments of the presentinvention, the cured encapsulant 14 may be used as a stop to provide forlevel (depth of placement) control for the lens 20. Such control overthe positioning of the lens 20 may facilitate the production of partswith more consistent optical performance.

As shown in FIG. 9C, the lens 20 in some embodiments of the present ispositioned without advancing into the cavity until it contacts the curedfirst quantity of encapsulant material 14 as a film of the encapsulantmaterial 16 remains therebetween. Thus, in some embodiments of thepresent invention, the device is configured so that the lens 20 may beadvanced to a position established by the first quantity of encapsulantmaterial 14, which position may be established with or without contactof the lens 20 to the cured encapsulant material 14 in variousembodiments of the present invention.

FIGS. 10A-10C illustrate methods of packaging a light emitting device,using the structural characteristics of a reflector cup for meniscuscontrol, according to some embodiments of the present invention. Theoperations illustrated in FIGS. 10A-10C utilize the reflector cup 4Billustrated in FIG. 7 and the double curing operations also previouslydescribed. As shown in FIG. 10A, a first quantity 14 of encapsulantmaterial is deposited in the reflective cavity 15 of the package 10C. Insome embodiments of the present invention, the first quantity 14 may bedispensed using a separate (wetting) dispense and a second dispense.With proper control of the amount of encapsulant material dispensed,surface tension will cause the liquid encapsulant material 14 to clingto the inner lip 22, forming a convex meniscus as illustrated in FIG.10A at a height indicated at 14A. Thus, the inner lip 22 may be used toprevent the dispensed encapsulant material 14 from contacting andwicking up the upper sidewall 5 and forming a concave meniscus as shownin FIG. 1.

The dispensed encapsulant material 14 is cured, for example, by heating,and may shrink down to a height indicated at 14B. As shown in FIG. 10B,a second quantity 16 of encapsulant material is then dispensed into thereflective cavity 15 on the cured first quantity 14 of encapsulantmaterial. In some embodiments, as illustrated in FIG. 10B, the secondquantity 16 of encapsulant material clings to the outer lip 26′, forminga convex meniscus. Thus, the outer lip 26′ may be used to prevent thedispensed second quantity 16 of encapsulant material from contacting andwicking up the upper sidewall 5 and forming a concave meniscus as shownin FIG. 1.

Referring to FIG. 10C, the lens 20 is inserted into reflective cavity 15and brought into contact with the uncured liquid encapsulant material16. As such, the encapsulant material 16 may be squeezed out fromunderneath the lens 20. However, in some embodiments of the presentinvention, instead of squeezing out onto the exposed upper surfaces ofthe reflector cup and the lens (as shown in FIG. 2), the excess of theencapsulant material 16 is squeezed into and received by the second moat24, thus limiting wicking of the encapsulant material 16 up the sidewall5 even after the lens 20 is inserted and the convex meniscus shown inFIG. 10B is displaced. The encapsulant material 16 is then cured toattach the lens 20 in the package TOC and to solidify the encapsulantmaterial 16.

FIG. 10C further illustrates that, in some embodiments of the presentinvention, the other lip 26′ may be used as a stop to provide for level(depth of placement) control for the lens 20. Such control over thepositioning of the lens 20 may facilitate the production of parts withmore consistent optical performance. In this embodiment, the lensplacement does not depend on the amount of shrinkage of the encapsulantduring the first cure step. For the embodiments illustrated in FIG. 10C,as contrasted with those illustrated in FIG. 9C, the placement of thelens 20 need not be dependent on the amount of shrinkage of the firstquantity 14 of encapsulant material as the placement depth is, instead,defined by the height of the outer lip 26′. As such, in some embodimentsof the present invention, the placement may be more exact, which mayresult in improved optical performance of the package 10C.

Methods for packaging a light emitting device using a first (wetting)dispense according to some embodiments of the present invention will nowbe further described with reference to the flowchart illustrations ofFIG. 11. As shown in FIG. 11, operations may begin at Block 1100 bymounting the light emitting device on a bottom surface of a reflectivecavity. The mounted light emitting device has an associated heightrelative to the bottom surface of the reflective cavity. A firstquantity of encapsulant material is dispensed into the reflective cavityincluding the light emitting device (Block 1120).

The first quantity may be sufficient to substantially cover the lightemitting device without forming any air pockets in the encapsulantmaterial. In some embodiments of the present invention, the firstquantity may be sufficient to wet the light emitting device withoutfilling the reflective cavity to a level exceeding the height of thelight emitting device. In other embodiments of the present invention,the time/speed of dispense of the encapsulant material may be changed toreduce the formation of air pockets in the encapsulant material. In yetfurther embodiments, a single dispense may be used, for example, with aslow dispense rate, from a small dispense needle, low pressure, or thelike, allowing an air pocket to potentially form and then cave/collapsebefore enough encapsulant material has been dispensed to preventcollapse of the air pocket. Thus, the first (wetting) dispense andsecond dispense may be provided by a continuous dispense at a selectedrate of a selected viscosity encapsulant material that allowscave/collapse of a formed air pocket during the dispense operation Thefirst quantity may be sufficient to wet the light emitting devicewithout filling the reflective cavity to a level exceeding the height ofthe light emitting device.

A second quantity of encapsulant material is dispensed onto the firstquantity of encapsulant material (Block 1130). The dispensed first andsecond quantity of encapsulant material are then cured (Block 1140). Insome embodiments of the present invention, the first dispensed wettingquantity of encapsulant material may be cured before the remainder ofthe encapsulant material is dispensed.

The first quantity 12, 14 and the second quantity 16 of the encapsulantmaterial may be the same or different materials. Similarly, the first 12and second 14 portions of the first quantity of the encapsulant materialmay be the same or different materials. Examples of materials that maybe used as an encapsulant material in various embodiments of the presentinvention include silicon.

Operations related to packaging a semiconductor light emitting deviceaccording to some embodiments of the present invention using meniscuscontrol will now be described with reference to the flowchartillustration of FIG. 12. As shown in FIG. 12, operations may begin atBlock 1200 with mounting of the light emitting device 103 in areflective cavity 15 of a reflector 5. Encapsulant material is dispensedinto the reflective cavity 15 including the light emitting device 103therein to cover the light emitting device 103 and to form a convexmeniscus of encapsulant material in the reflective cavity extending froman edge of the moat without contacting the upper sidewall 5 of thereflector 4, 4A, 4B (Block 1210). More generally, operations at Block1210 provide for formation of a convex meniscus extending from an outeredge of the meniscus that is at a height positioning the outer edge ofthe meniscus within the reflective cavity 15. For example, selection ofmaterials used for the upper sidewall 5 and the encapsulant material 12,14, 16 may facilitate formation of a convex, rather than concave,meniscus extending into the reflective cavity 15. The encapsulantmaterial 12, 14, 16 is in the reflective cavity 15 (Block 1220). Inembodiments where a lens 20 is included in the package 10A, 10B, 10C,insertion of the lens 20 may include collapsing the convex meniscus andmoving a portion of the encapsulant material 12, 14, 16 into the moat18, 24 with the lens 20 and then curing the encapsulant material 12, 14,16 to attach the lens 20 in the reflective cavity 15. Alternatively, theencapsulant material 12, 14, 16 may be cured to form a lens for thepackaged light emitting device 103 from the encapsulant material 12, 14,16 and the encapsulant material 12, 14, 16 may be dispensed to form aconvex meniscus providing a desired shape of the lens.

Embodiments of methods of packaging a semiconductor light emittingdevice 103 in a reflector 4, 4A, 4B having a moat 18, 24 positionedbetween a lower 6 and an upper 5 sidewall thereof, the upper 5 and lower6 sidewall defining a reflective cavity 15, using a multiple dispenseand/or cure operation will now be further described with reference toFIG. 13. As shown in the embodiments of FIG. 13, operations begin atBlock 1300 by dispensing a first quantity 14 of encapsulant materialinto the reflective cavity 15 to form a first convex meniscus. The firstquantity 14 of encapsulant material is cured (Block 1310). A secondquantity 16 of encapsulant material is dispensed onto the cured firstquantity 14 of encapsulant material to form a second convex meniscus ofencapsulant material in the reflective cavity 15 extending from an edgeof the moat 18, 24 without contacting the upper sidewall 5 of thereflector 4, 4A, 4B (Block 1320).

The second convex meniscus and the first convex meniscus of encapsulantmaterial may both extend from the same edge of the moat 18 asillustrated in FIG. 8B. However, in other embodiments of the presentinvention, the moat 18, 24 may have an inner edge and an outer edge,such as the first lip 22 and the second lip 26, 26′, and the secondconvex meniscus of encapsulant material extends from the outer edge(second lip 26, 26′) of the moat 18, 24 and the first convex meniscus ofencapsulant material extends from the inner edge (first lip 22) of themoat 18, 24. Thus, using the first lip 22, the inner moat 18 may beconfigured to limit wicking of encapsulant material 14 outwardly alongthe horizontal shoulder portion 8 to allow formation of a first convexmeniscus of encapsulant material dispensed into the reflective cavity15. Using the second lip 26, 26′, the outer moat 24 may be configured tolimit wicking of encapsulant material outwardly along the horizontalshoulder portion 8 to allow formation of a second convex meniscus ofencapsulant material dispensed into the reflective cavity 15.

In some embodiments of the present invention including a lens, the lens20 is positioned in the reflective cavity 15 proximate the dispensedsecond quantity 16 of encapsulant material (Block 1330). Positioning thelens 20 may include collapsing the second convex meniscus and moving aportion of the second quantity 16 of encapsulant material into the outermoat 24 with the lens 20 as illustrated in FIGS. 9C and 10C. Inaddition, as illustrated in FIG. 10C, the second lip 26′ may have aheight greater than that of the first lip 22. The height of the secondlip 26′ may be selected to provide a desired position for the lens 20and the lens 20 may be moved into the reflective cavity 15 until itcontacts the second lip 26′. In other embodiments of the presentinvention, as illustrated in FIG. 9C, the lens 20 is advanced into thereflective cavity 15 until it contacts the cured first quantity 14 ofencapsulant material and the dispensed first quantity 14 of encapsulantmaterial sufficient to establish a desired position for the lens 20 inthe reflective cavity 15. The dispensed second quantity 16 ofencapsulant material is cured to attach the lens 20 in the reflectivecavity 15 (Block 1340).

The flowcharts of FIGS. 11-13 and the schematic illustrations of FIGS.8A-8C, 9A-9C and 10A-10C illustrate the functionality and operation ofpossible implementations of methods for packaging a light emittingdevice according to some embodiments of the present invention. It shouldbe noted that, in some alternative implementations, the acts noted indescribing the figures may occur out of the order noted in the figures.For example, two blocks/operations shown in succession may, in fact, beexecuted substantially concurrently, or may be executed in the reverseorder, depending upon the functionality involved.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. Therefore, it is to be understood that the foregoing isillustrative of the present invention and is not to be construed aslimited to the specific embodiments disclosed, and that modifications tothe disclosed embodiments, as well as other embodiments, are intended tobe included within the scope of the appended claims. The invention isdefined by the following claims, with equivalents of the claims to beincluded therein.

1. A packaged semiconductor limit emitting device comprising: areflector having a lower sidewall portion defining a reflective cavity,a substantially horizontal shoulder portion extending outwardly from thelower sidewall portion, the horizontal shoulder portion having acircumferentially extending moat formed therein and an upper sidewallportion extending upwardly from the horizontal shoulder portion, whereinan edge of the moat is configured to limit wicking of encapsulantmaterial outwardly along the horizontal shoulder portion to allowformation of a convex meniscus of encapsulant material dispensed intothe reflective cavity; a light emitting device positioned in thereflective cavity; and an encapsulant material in the reflective cavityand covering the light emitting device.
 2. A packaged semiconductorlight emitting device comprising: a reflector having a lower sidewallportion defining a reflective cavity, wherein the lower sidewall portionis sloped, a substantially horizontal shoulder portion extendingoutwardly from the lower sidewall portion, the horizontal shoulderportion having a circumferentially extending moat formed therein and anupper sidewall portion extending upwardly from the horizontal shoulderportion; a light emitting device positioned in the reflective cavity;and an encapsulant material in the reflective cavity and covering thelight emitting device.
 3. The device of claim 2 wherein the lightemitting device comprises a light emitting diode (LED).
 4. The device ofclaim 2 wherein the encapsulant material comprises a silicone gel. 5.The device of claim 2 wherein the encapsulant material includes a lightconverting material.
 6. The device of claim 2 wherein the encapsulantmaterial includes a first region displaced from the light emittingdevice that is substantially free of phosphor and a second regionbetween the first region and the light emitting device that includes aphosphor.
 7. The device of claim 6 wherein the device further comprisesa lens attached to the first region of the encapsulant material andextending therefrom.
 8. The device of claim 2 further comprising a lensextending from the encapsulant material over the light emitting device.9. A reflector for a semiconductor light emitting device, comprising: alower sidewall portion defining a reflective cavity, wherein the lowersidewall portion is sloped; a substantially horizontal shoulder portionextending outwardly from the sloped lower sidewall portion, thehorizontal shoulder portion having a circumferentially extending moatformed therein; and an upper sidewall portion extending upwardly fromthe horizontal shoulder portion.
 10. The reflector of claim 9 wherein anedge of the moat is configured to limit wicking of encapsulant materialoutwardly along the horizontal shoulder portion to allow formation of aconvex meniscus of encapsulant material dispensed into the reflectivecavity.
 11. The reflector of claim 10 wherein the edge of the moatcomprises a lip.
 12. The reflector of claim 10 wherein the lip has apeak having a radius of curvature of less than about 50 micrometers. 13.The reflector of claim 9 wherein the moat comprises a circumferentiallyextending inner moat positioned proximate the lower sidewall portion anda circumferentially extending outer moat positioned between the innermoat and the upper sidewall portion.
 14. The reflector of claim 13wherein an edge of the inner moat is configured to limit wicking ofencapsulant material outwardly along the horizontal shoulder portion toallow formation of a first convex meniscus of encapsulant materialdispensed into the reflective cavity and an edge of the outer moat isconfigured to limit wicking of encapsulant material outwardly along thehorizontal shoulder portion to allow formation of a second convexmeniscus of encapsulant material dispensed into the reflective cavity.15. The reflector of claim 14 wherein the edge of the first moatcomprises a first lip and wherein the edge of the second moat comprisesa second lip.
 16. The reflector of claim 14 wherein the first lip has apeak having a radius of curvature of less than about 50 micrometers andwherein the second lip has a peak having a radius of curvature of lessthan about 50 micrometers.
 17. The reflector of claim 14 wherein thefirst moat and the second moat are stamped features of the horizontalshoulder portion.
 18. The reflector of claim 14 wherein the second moathas a width extending from the second lip to the upper sidewall portion.19. The reflector of claim 14 wherein the lower sidewall portion issubstantially conical and has a minimum diameter of from about 1.9millimeters (mm) to about 3.2 mm and a maximum diameter of from about2.6 mm to about 4.5 mm and a height of from about 0.8 mm to about 1.0mm.
 20. The reflector of claim 19 wherein the upper sidewall portion issubstantially oval and has an inner diameter of from about 3.4millimeters (mm) to about 4.2 mm and a height of from about 0.6 mm toabout 0.7 mm.
 21. The reflector of claim 19 wherein the horizontalshoulder portion has a width from the lower sidewall portion to theupper sidewall portion of from about 0.4 mm to about 0.7 mm.
 22. Thereflector of claim 21 wherein the first moat has a width from about 0.3millimeters (mm) to about 0.4 mm and wherein the second moat has a widthof from about 0.3 mm to about 0.4 mm.
 23. The reflector of claim 22wherein the edge of the first moat comprises a first lip having a heightrelative to bottom end of the lower sidewall portion of from about 0.3millimeters (mm) to about 0.4 mm and wherein the edge of the second moatcomprises a second lip having a height relative to bottom end of thelower sidewall portion of from about 0.79 mm to about 0.85 mm.
 24. Thereflector of claim 22 wherein the edge of the first moat comprises afirst lip having a height relative to bottom end of the lower sidewallportion of from about 0.79 millimeter (mm) to about 0.85 mm and whereinthe edge of the second moat comprises a second lip having a heightrelative to bottom end of the lower sidewall portion of from about 0.9mm to about 1.0 mm.